The present invention relates generally to the field of electronic data storage and retrieval systems. In particular, the present invention relates to a magnetic writing device.
A magnetic data storage and retrieval system typically includes a writer for storing magnetically encoded information on a magnetic media and a reader for retrieving the magnetically encoded information from the magnetic media. The writer typically consists of two magnetic poles, also known as a magnetic core, separated at the air bearing surface (ABS) of the write head by a write gap and connected to each other at a region away from the ABS. Positioned between the two poles are one or more conductive coil layers encapsulated by insulating layers. To write data to the magnetic media, a time varying write current is caused to flow through the conductive coil, which in turn produces a time varying magnetic field through the poles. The magnetic media is then passed near the ABS of the writer at a predetermined distance such that the media passes through the magnetic field. As the write current changes in direction and magnitude, the magnetic field changes in direction and magnitude as well. In a typical magnetic writer, a sufficient magnetic field must be applied to the disc medium in order to write to the magnetic media. More specifically, the field produced by the head at the magnetic media must be of sufficient magnitude to overcome the high coercivity of the magnetic media.
The increasing density of stored information on magnetic storage devices necessitates the availability of writing methods that allow magnetic writing with high a real density. Magnetic media which support a high density of stored information and at the same time are stable (stored information does not degrade with time) are usually characterized by high coercivity and high magnetic anisotropy. Typically, writing on such media (switching the local direction of magnetization) requires a high magnitude magnetic field. Currently, magnetic writers are based on the idea of focusing the magnetic field from the pole towards the magnetic media. Several factors, however, hinder further advance of this writing method, including the value of saturation magnetization of top pole materials, process technologies involved in producing a top pole of a very small size, and difficulties in further reduction of the flight height.